Autothermal reformer-reforming exchanger arrangement for hydrogen production

• US 7,220,505 B2
• Filed: 03/12/2004
• Issued: 05/22/2007
• Est. Priority Date: 03/18/2003
• Status: Active Grant

• Current Assignee: Kellogg Brown & Root LLC (KBR Incorporated)
• Original Assignee: Kellogg Brown & Root LLC (KBR Incorporated)
• Inventors: Malhotra, Avinash, Gosnell, James Hanlan
• Primary Examiner(s): Langel; Wayne A.
• Application Number:
  US10/708,583
• Publication Number:
  US 20040182002A1
• Time in Patent Office: 1,166 Days
• Field of Search: 252/373, 423/650, 423/651, 423/652, 423/653, 423/654, 208/62, 208/63, 208/64, 208/66, 429/17
• US Class Current: 429/411
• CPC Class Codes: B01J 2208/00309 with two or more reactions in heat exchange with each other, such as an endothermic reaction in heat exchange with an exothermic reaction
• CPC Class Codes: B01J 2208/00504 by means of a burner
• CPC Class Codes: B01J 2208/0053 Controlling multiple zones along the direction of flow, e.g. pre-heating and after-cooling
• CPC Class Codes: B01J 2219/00006 Large-scale industrial plants
• CPC Class Codes: B01J 8/0488 the beds being placed in separate reactors
• CPC Class Codes: B01J 8/0496 Heating or cooling the reactor
• CPC Class Codes: B01J 8/065 Feeding reactive fluids
• CPC Class Codes: B01J 8/067 Heating or cooling the reactor B01J8/062 takes precedence
• CPC Class Codes: C01B 2203/0233 the reforming step being a steam reforming step
• CPC Class Codes: C01B 2203/0244 the reforming step being an autothermal reforming step, e.g. secondary reforming processes
• CPC Class Codes: C01B 2203/0283 containing a CO-shift step, i.e. a water gas shift step
• CPC Class Codes: C01B 2203/0405 Purification by membrane separation
• CPC Class Codes: C01B 2203/042 Purification by adsorption on solids
• CPC Class Codes: C01B 2203/0844 the non-combustive exothermic reaction being another reforming reaction as defined in groups C01B2203/02 - C01B2203/0294
• CPC Class Codes: C01B 2203/141 At least two reforming, decomposition or partial oxidation steps in parallel
• CPC Class Codes: C01B 2203/142 At least two reforming, decomposition or partial oxidation steps in series
• CPC Class Codes: C01B 2203/82 Several process steps of C01B2203/02 - C01B2203/08 integrated into a single apparatus
• CPC Class Codes: C01B 3/382 Multi-step processes
• CPC Class Codes: C01B 3/384 the catalyst being continuously externally heated
• CPC Class Codes: C01B 3/48 followed by reaction of water vapour with carbon monoxide
• CPC Class Codes: H01M 8/0618 : Reforming processes, e.g. autothermal, partial oxidation or steam reforming
• CPC Class Codes: H01M 8/0668 : Removal of carbon monoxide or carbon dioxide
• CPC Class Codes: Y02E 60/50 : Fuel cells
• CPC Class Codes: Y02P 20/129 : Energy recovery, e.g. by cogeneration, H2recovery or pressure recovery turbines

Abstract

Low-energy, low-capital hydrogen production is disclosed. A reforming exchanger 14 is placed in parallel with an autothermal reformer (ATR) 10 to which are supplied a preheated steam-hydrocarbon mixture. An air-steam mixture is supplied to the burner/mixer of the ATR 10 to obtain a syngas effluent at 650°-1050° C. The effluent from the ATR is used to heat the reforming exchanger, and combined reformer effluent is shift converted and separated into a mixed gas stream and a hydrogen-rich product stream. High capital cost equipment such as steam-methane reformer and air separation plant are not required.

Claims

1. A process for producing hydrogen, comprising:

catalytically reforming a first hydrocarbon portion with steam and excess air in an autothermal reactor to produce a first syngas effluent at a temperature from 650°

to 1050°

C.;

supplying the first syngas effluent to a reforming exchanger;

passing a second hydrocarbon portion with steam through a catalyst zone in the reforming exchanger to form a second syngas effluent;

discharging the second syngas effluent from the catalyst zone adjacent the inlet to form a syngas admixture with the first syngas effluent;

passing the admixture across the catalyst zone in indirect heat exchange therewith to cool the admixture and heat the catalyst zone;

collecting the cooled admixture from an outlet of the reforming exchanger;

shift converting the admixture to obtain a carbon dioxide-rich gas stream lean in carbon monoxide; and

separating the carbon dioxide-rich gas stream to form a hydrogen-lean, mixed gas stream comprising nitrogen and carbon dioxide and a hydrogen-rich product stream.

2. The process of claim 1, wherein the mixed gas separation comprises membrane separation.

3. The process of claim 1, wherein the mixed gas separation comprises pressure swing adsorption.

4. The process of claim 1, wherein the catalyst zone comprises catalyst tubes, the process further comprising:

supplying the first syngas effluent to a shell-side of the reformer;

supplying the second hydrocarbon portion with steam through the catalyst tubes;

discharging the second syngas effluent from the catalyst tubes adjacent the shell-side inlet to form the syngas admixture.

5. The process of claim 1 wherein the carbon dioxide-rich gas stream from the shift conversion comprises a molar ratio of hydrogen to nitrogen less than 3.

6. The process of claim 1 wherein the mixed gas separation is free of cryogenic separation.

7. The process of claim 1 wherein the process is free of air separation.

8. The process of claim 1 wherein a proportion of the first hydrocarbon portion relative to a total of the first and second hydrocarbon portions is from 55 to 85 percent.

9. The process of claim 1 wherein a proportion of the first hydrocarbon portion relative to a total of the first and second hydrocarbon portions is from 60 to 80 percent.

10. The process of claim 1 wherein the hydrogen product stream has a purity of at least 70 volume percent.

11. The process of claim 10, wherein the hydrogen product stream has a purity of from 90 to 99.5 volume percent.

12. The process of claim 1, wherein the hydrogen product stream has a purity of at least 95 volume percent.

13. The process of claim 1, wherein the hydrogen product stream has a purity of at least 97 volume percent.

14. The process of claim 1, wherein the hydrogen product stream has a purity of at least 98.5 volume percent.

15. A process for generating an electrical current comprising the process of claim 1 and supplying the hydrogen-rich product stream to a fuel cell.

16. A hydrotreating process comprising the process of claim 1 and supplying the hydrogen-rich product stream to a hydrotreater.

17. The process of claim 1, wherein the reforming, shift conversion and mixed gas separation comprise a process pressure from 10 to 200 bars.

18. The process of claim 17, wherein the reforming, shift conversion and mixed gas separation comprise a process pressure of at least 30 bars.

19. The process of claim 1, further comprising compressing air to the catalytic reforming with a gas turbine drive and recovering heat from exhaust from the gas turbine.